From owner-freebsd-current Thu Feb 8 16: 5:24 2001 Delivered-To: freebsd-current@freebsd.org Received: from netau1.alcanet.com.au (ntp.alcanet.com.au [203.62.196.27]) by hub.freebsd.org (Postfix) with ESMTP id 41F5037B698 for ; Thu, 8 Feb 2001 16:05:05 -0800 (PST) Received: from mfg1.cim.alcatel.com.au (mfg1.cim.alcatel.com.au [139.188.23.1]) by netau1.alcanet.com.au (8.9.3 (PHNE_22672)/8.9.3) with ESMTP id LAA19033; Fri, 9 Feb 2001 11:00:21 +1100 (EDT) Received: from gsmx07.alcatel.com.au by cim.alcatel.com.au (PMDF V5.2-32 #37640) with ESMTP id <01JZWJYE5H5C8ZKKKC@cim.alcatel.com.au>; Fri, 9 Feb 2001 11:00:10 +1100 Received: (from jeremyp@localhost) by gsmx07.alcatel.com.au (8.11.1/8.11.1) id f19004V02770; Fri, 09 Feb 2001 11:00:04 +1100 (EST envelope-from jeremyp) Content-return: prohibited Date: Fri, 09 Feb 2001 11:00:04 +1100 From: Peter Jeremy Subject: Re: atomic_ question In-reply-to: <20010208222131.D81067@cicely5.cicely.de>; from ticso@cicely5.cicely.de on Thu, Feb 08, 2001 at 10:21:32PM +0100 To: Bernd Walter Cc: freebsd-current@FreeBSD.ORG Mail-followup-to: Bernd Walter , freebsd-current@FreeBSD.ORG Message-id: <20010209110004.D90937@gsmx07.alcatel.com.au> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-disposition: inline User-Agent: Mutt/1.2.5i References: <20010208182106.B80741@cicely5.cicely.de> <20010209075749.Z90937@gsmx07.alcatel.com.au> <20010208222131.D81067@cicely5.cicely.de> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 2001-Feb-08 22:21:32 +0100, Bernd Walter wrote: >On sparcv8 you don't have an operation doing conditionaly stores and >you don't have RMW operations. >The only way to do is to have a global lock variable on which you spin >until the current client finishes. The SPARC architecture supports SMP so there must be some synchronisation primitive that works between processors (disabling interrupts only works on the current processor). Normally the same primitive can be used to synchronise accesses within the same processor. I know the older SPARC's had a test-and-set instruction which was locked RMW - there must be something similar in v8 and v9. Peter To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message